I don't think so, especially with the Nx who come soon.

Because the psp was heavily...Really pirated outside of japan.

Software sales were horrible for most games, and that's why tons of jap games never even bother to release outside japan.

Probably no, the 3DS has got probably another 3 already released games that will crawl to it by end of gen (Fantasy Life) and then probably another 10 yet to be released games to pass 1m (Yokai Busters, Yokai 3, Fire Emblem, Zelda, Monster hunter X, MH Story, Pokemon Mystery Dungeon etc )

Is it really though? Nintendo's own Ips like Mario and Pokemon have always had huge attachment rates, this is nothing new.

My local gaming store has a bigger selection of PSP games than WII U games and they still sell a decent amount of them. 

OP: It seems highly unlikely as of now.

I doubt it, this is too hard.

Games I think will get to one milion:

- Pokemon Dungeon
- DQ8
- Youkai Watch Busters
- Fire Emblem
- Mario and Luigi - Paper Jam
- Legend of Zelda Triforce Heroes
- Animal Crossing Home Designer
- Rhythm Heaven

That means 9 to go. so games that are yet to be announced that will sell 1m:

- MH5
- One Pokemon game
- Yokai 3


That leaves 6 games to equal the PSP. It will be close, it depends on the NX a lot. I think they can easily produce a Kirby title, Pokemon spinoff, DK title, couple of Mario spinoffs to do that. I wouldn't be surprised about another Yokai game as well as Level-5 seem to be adamant on at least two games a year. So it's possible but it will be a tight race.

Well we Know that...

mario tennis will be 39...

so even if PSP goes to 60 we only need 22.

and we can be sure of...

40. Fire Emblem Fate
41. Dragon Quest Monsters: TW
42. Sonic Generations
43. Pilotwings
44. Fantasy Life
45. Dragon Quest Monsters 2
46. New AC Happy Home
47. New Yokai Watch
48. New Zelda
49. New Hyrule Warriors
50. New Dragon Quest VIII
51. New Pokemon Dungeon
52. New Mario & Luigi Paper Jam
53. New Chibi Robot (my personal guess i know)
54. New Wii remake exclusive for New 3DS (whatever this will be)
55. xxx
56. xxx
57. xxx
58. xxx
59. xxx
60. xxx
61. xxx

so 7 not yet announced.....

Unless Square Enix decides to re-print these games, they're not getting to 1 million.

I don't know if VGC tracks them or not but they are indeed still sold. In european countries the PSP sections still exist and some stores actually give it more space than the Wii U